sensor washers?

[JaneHibbert]

If I wanted to fit a water temperature sensor, or oil pressure sensor I know I just 'screw' one in, but do i need to use some sealer or a washer or something between the sensor and the engine to seal it? Maybe a copper washer? Thanks all.

[les]

If the sensor has a flange and screws in up to this flange then use a copper washer. Some sensors have a tapered thread that gets tighter the further in you screw it, no washer used on this type.( oil warning lamp sensor for example)